Carburetor main fuel nozzle



Feb. 2, 1965 F. J. MARSEE ETAL CARBURETOR MAIN FUEL NOZZLE Filed July16, 1962 Q JM an ATTO/P/VEY United States Patent Oil" 3,168,599CARZBURETGR MAIN FUEL NOZZLE Frederick J. Marsee, Hazel Park, Neil M.Romeo, St.

Clair Shores, and John Dirda, Detroit, Mich., assignors to HolleyCarburetor Company, Warren, Mich., a corporation of Michigan Filed July16, 1962, Ser. No. 209,823 3 Claims. (Cl. 261-65) This invention relatesgenerally to carburetors for internal combustion engines, and morespecifically to a novel carburetor and main nozzle construction.

Each carburetor design and application presents its own peculiarproblems of proper distribution of fuel and air mixture to the engine,and it has been found that variations in main nozzle design maysubstantially effect distribution. Also, each carburetor design presentspeculiar problems in the manner in which the main nozzle must be formedor assembled in the carburetor.

A main object of this invention is to provide a nozzle design which iscapable of thoroughly mixing and dispersing the fuel and air mixture, inorder that proper distribution to the engine will be attained.

A specific object of the invention is to provide a novel nozzle andcarburetor structure in which the nozzle is easily manufactured andadaptable to be inserted into the main Well chamber of the carburetor.

Other objects and advantages of the invention will become apparent whenreference is made to the accompanying illustrations wherein:

FIGURE 1 is an elevational view, with portions thereof broken away andin cross section, illustrating a carburetor embodying the invention andmounted on an intake manifold.

FIGURE 2 is an enlarged perspective view of a nozzle embodying theinvention.

Referring to the drawings in greater detail, FIGURE 1 illustratesgenerally a carburetor 16, which may comprise upper and lower portions12 and 14, mounted on m engine intake manifold 16. The carburetorcomprises an induction passage 18 having the usual choke plate 20',venturi 22 and throttle plate 24 therein, as well as the novel main fuelnozzle 26. The fuel reservoir 28 is generally formed as an integral partof the carburetor 10', and it has associated therewith a main meteringsystem 30. A conduit 32 containing a main metering jet 34 communieatesbetween the fuel reservoir 28 and the main well 36 of the main fuelmetering system 30.

A main well tube 38 is pressed into the upper body 12 of the carburetor10, as at 40, so as to be suspended in the main well 36 When theportions 12 and 14 are assembled. The main well tube 38 contains aplurality of bleed passages 42 so as to communicate the inside of thetube with the main well chamber 36. A conduit 44 and a restriction 46communicate between the open top 48 of the main well tube 38 and theinduction passage 18.

The novel main fuel nozzle 26 is associated and cooperates with thecarburetor main metering system 30 by virtue of having its tubular inletend 50 press fitted into a bore 52 in the lower body 14 of thecarburetor 10, so as to surround the main well tube 38. That is, thetubular end 50 forms a portion of the main well 36. A discharge passage54 through the stem 56 of the main nozzle 26 communicates between themain well 36 and the induction passage 18. An anti-siphon air bleed 58communicates between the inlet end 60' of the discharge passage 54 andthe conduit 44 leading to the induction passage 18.

As is better illustrated in FIGURE 2, the novel main nozzle 26, whichmay comprise a one piece casting, is formed so as to include acylindrical end 58 adapted to be press fitted into a counter-bored upperend 52 of the main fuel well 36 so as to form, with its inside wall 62 acontinuation of the main well chamber 36. The upper portion of thecylindrical end 50 is extended tangentially from two sides 64 and 66thereof, so as to enable formation of a point of intersection 68 betweenthe uppermost end of the main well chamber 36 and the passage 54extending axially through the downwardly sloping stem 56, the latterentering the induction passage 18 in the vicinity of the venturi 22. Thesurface 70 at the inlet end 60 is perpendicular to the axis of the stem56.. At the discharge end 72 of the stem 56 there is formed a pair ofdiverging prongs 74 and 76 having a separating fillet therebetweensubstantially equal to the diameter of the passage 54. A verticalpassage 78 is formed through the center of a rounded protuberance 80which connects the discharge end 72 of the stem 56 to the separatedprongs 74 and 76.

Operation When the engine is operating, fuel already partially mixedwith air is drawn in the well known manner into the main well 36, intothe clearance 82 between the cylindrical end 50 of the nozzle 26 and themain well tube 38 and thence through the passage 54 and outlet 84 intothe induction passage 18. As the fuel is discharged through the outlet84, it is intercepted by a downward flow of air through the centrallylocated passage 78. A portion of the resulting fuel-air mixture is thendeflected upon impact with the two prongs 74 and 76, while anotherportion of the mixture passes between the prongs. The various portionsof the fuel-air mixture are thus distributed in a controlled manner byand through the prongs 74 and 76, depending upon the preselectedattitude and shape of the prongs.

Actual tests have proven that a fuel-air mixture dispersed in thismanner upon being discharged into the air stream through the inductionpassage 18 has resulted in an ideal distribution to the cylinders of theengine.

It is also apparent that this nozzle construction, in addition toproviding ideal distribution of fuel, provides a Very convenient methodof assembling a separately formed nozzle into the carburetor. Thetubular end 50 of the nozzle is merely inserted into the bore 52 in thelower portion 14 of the carburetor, and the gasket 85 and upper portion12 of the carburetor are then assembled on the lower portion 14 so as toretain the nozzle 26.

Although but one embodiment of the invention has been shown anddescribed, it is apparent that other .modifications thereof may be madewithout exceeding the scope of the appended claims.

What we claim as our invention is:

1. Carburetor, comprising assembled upper and lower body portions; amain fuel metering system including a main well chamber and a main welltube, an induction passage having a venturi and throttle plate therein,and a main fuel nozzle having a hollow mounting portion inserted in andforming a part of said main well chamber, a stem extending from a pointadjacent the top of said main well chamber to substantially the centerof said venturi, a plurality of downwardly extending protrusions, abridge-like portion formed between the tops of said protrusions and theend of said stem positioned in said induction passage, and a verticalpassage formed through said bridge-like portion.

2. In a carburetor having upper and lower body portions, a main fuelmetering system including a main well chamber and a main well tube, andan induction passage having a venturi and throttle plate the-rein, amain fuel nozzle, said nozzle comprising a cylindrical portion forinsertion in said main well as a part of the wall of said main Well, adownwardly sloping stem extending from said cylindrical portion and intosaid induction passage, an

Patented Feb. 2, 1965 1 axial passageway through said stem, a pair oflegs opposite the outlet end of said stem and connected to the top ofsaid outlet end by a bridge-like portion, and a passage through saidbridge-like portion.

3. In a carburetor having assembled upper and lower body portions, amain fuel metering system including a main well chamber and a main welltube, and an induction passage having a venturi and throttle platetherein, a main fuel nozzle, said nozzle comprising a tubular portioninserted into said main well with the top surface thereof level with thetop surface of said lower body and the inside surface thereof forming avertical extension of said main well chamber, an integral portionextending from substantially the upper half of said tubular portion andtoward said induction passage, a stem extending from said integralportion in a downwardly sloping attitude into said induction passage andterminating at a point substantially at the center of said venturi, apassageway extending radially through the length of said stem, aprotuberance extending from the end of said stem and having a pair ofvertical legs extending downwardly therefrom toward said throttle platewith the top of the opening be tween said pair of vertical legs beingsubstantially level with the axis of said passageway, and a verticalopening formed through said protuberance.

References Cited in the file of this patent UNITED STATES PATENTS2,615,695 Winkler Oct. 28, 1952 2,986,378 Moseley May 30, 1961 3,076,639Szwargulski et a1 Feb. 5, 1963 3,081,986 Egerer Mar. 19, 1963 3,089,634Smith May 14, 1963 FOREIGN PATENTS 602,404 France Dec. 23, 1925 881,461Great Britain Nov. 1, 1961

1. CARBURETOR, COMPRISING ASSEMBLED UPPER AND LOWER BODY PORTIONS; A MAIN FUEL METERING SYSTEM INCLUDING A MAIN WELL CHAMBER AND A MAIN WELL TUBE, AN INDUCTION PASSAGE HAVING A VENTURI AND THROTTLE PLATE THEREIN, AND A MAIN FUEL NOZZLE HAVING A HOLLOW MOUNTING PORTION INSERTED IN AND FORMING A PART OF SAID MAIN WELL CHAMBER, A STEM EXTENDING FROM A POINT ADJACENT THE TOP OF SAID MAIN WELL CHAMBER TO SUBSTANTIALLY THE CENTER OF SAID VENTURI, A PLURALITY OF DOWNWARDLY EXTENDING PROTRUSIONS, A BRIDGE-LIKE PORTION FORMED BETWEEN THE TOPS OF SAID PROTRUSIONS AND THE END OF SAID STEM POSITIONED IN SAID INDUCTION PASSAGE, AND A VERTICAL PASSAGE FORMED THROUGH SAID BRIDGE-LIKE PORTION. 